Methods for deinking UV prints

Abstract

The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

The invention claimed is: 
     
       1. A process for preparing a deinked pulp, comprising the steps of: 
       disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and 
       applying a mechanical process to the waste paper slurry having a solids content of 0.5 to 5.0% by weight using a rotary disintegrator; 
       wherein the rotary disintegrator comprises stationary blades and rotating blades, so that inks can be detached/pulverized from a waste paper pulp when a feed stream passes between the stationary blades and the rotating blades, and 
       wherein the rotating blades have a blade width of 1.0 to 10 mm, and the stationary blades have a blade width of 0.3 to 2.0 mm. 
     
     
       2. The process of  claim 1 , comprising removing inks to the outside by flotation before the step of applying a mechanical process. 
     
     
       3. A process for making paper, comprising converting a raw material containing the deinked pulp prepared by the process of  claim 1  into paper. 
     
     
       4. A process for making paper, comprising converting a raw material containing the deinked pulp prepared by the process of  claim 2  into paper. 
     
     
       5. The process of  claim 1 , wherein the rotating blades have a blade width of 1.2 to 5.0 mm, and the stationary blades have a blade width of 0.5 to 1.4 mm. 
     
     
       6. The process of  claim 1 , wherein the rotating blades have a conical shape. 
     
     
       7. The process of  claim 1 , wherein the mechanical process is applied at 5 to 80° C.